The present invention relates to refrigerant systems of the type circulating high pressure refrigerant from a compressor through a condenser and expansion device, such as a thermal expansion valve, to an evaporator for absorption of heat vaporization and return to the compressor inlet. The present invention relates particularly to such refrigerant systems employed for air conditioning the passenger compartment of a motor vehicle.
In the design and manufacture of air conditioning systems for motor vehicles, it has been found difficult to provide suitable conduit connections between the various system components such as the evaporator, condenser and compressor during final assembly of the vehicle particularly in high volume, mass production, as is the case for passenger cars and light truck vehicles. In mass production of such systems, problems have been encountered with leakage of the refrigerant, particularly on the high pressure side of the system between the compressor and the expansion device.
In mass production of motor vehicles with air conditioning systems, it is desired to have quick-connect type fittings for attachment of the hoses and tubes to compressor, condenser and evaporator in order to eliminate the need for the use of tools and time consuming operations during assembly to thereby minimize the manufacturing costs of the vehicle. Heretofore, automotive air conditioning systems employing block type thermal expansion valves as the expansion device have utilized ported header blocks with the tubes welded or mechanically attached thereto prior to assembly, which blocks are subsequently attached to the expansion valve body with o-ring seals about the ports. This type of connection requires mechanical fasteners such as bolts threaded into the valve block for attachment of the header block thereto; and, can be extremely difficult to attach when the expansion valve is located near the engine compartment bulkhead or fire wall. This location for the expansion valve is often chosen to shorten the length of conduits between the expansion device and the evaporator or endothermic heat exchanger located within the passenger compartment. In many passenger and light truck motor vehicles it is difficult for personnel on the vehicle assembly line to attach the conduits to the expansion valve because of tight clearances between the surrounding vehicle components within the engine compartment.
Thus, it has been desired to provide a way or means of connecting vehicle air conditioning system conduits to an expansion valve and providing for mounting of the expansion valve in such a manner as to reduce the cost of the system assembly in vehicle production, to render the assembly operations easily accessible by the vehicle assembly personnel and to provide for seal integrity of the refrigerant circulating through the system.